First, with respect to stepped hull boats, such hull configurations are well known. Stepped hulls are used in general to reduce drag. One example of a stepped hull is shown in U.S. Pat. No. 4,027,613. Other stepped hull designs are shown in U.S. Pat. Nos. 6,415,731 and 6,925,983. A stepped hull is advantageous, including as indicated above, the reduction of drag, with resulting increased hull efficiency relative to a similar hull which is non-stepped. Stepped designs have been used in various general hull configurations, including deep-V mono-hull configurations, hydroplane-type hulls and tunneled hulls. Conventional stepped hull configurations, however, are fixed, i.e. the position and configuration of the step or steps cannot be altered after the hull is constructed. The effectiveness of stepped hull configurations varies. One stepped hull configuration may be advantageous in one type of sea condition to produce a better ride, while in other sea conditions a different stepped hull configuration might be preferred. Various trimming techniques can be used to modify or change the effect of a stepped hull configuration to produce a particular effect, including improvement in handling and/or performance, although trim tabs can create drag.
With regard to performance in particular, it is desirable in some cases to change the running of the boat, including changing the position of the bow and stern of the boat during operation, to obtained desired speed and/or other performance considerations, as well as maintaining a desired ride. Such adjustments can be conventionally achieved by adjusting engine trim, which may not be possible in those cases where the engine is fixed. In addition, the type of propeller can also be changed to change performance and/or ride characteristics. This will often, however, be inconvenient and still may not produce the desired result. As indicated above, trim tabs are useful but can produce drag.
It is hence desirable to provide a type of hull configuration, including stepped hulls, in which the hull and/or the steps in the hull can be conveniently adjusted to accommodate different sea conditions, as well as provide different performance characteristics. It is also desirable to have a hull arrangement by which the bow or the stern can be raised or lowered.